Gold recovery device



Dec. 15, 1936. A. TRAYMAN GOLD RECOVER-Y DEVICE Filed Sept. '7, 1955 2 n m on Mm H mm 9 NEW 2 &

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Patented Dec. 15, 1936 UNETD STATES .ATENT orrlcs GOLD RECOVERY DEVICE Albert Trayrnan, Seattle, Wash.

Application September '7, 1935, Serial No. 39,598 5Claims. (or. 209-184) My invention relates to the recovery of gold, particularly fine gold known as flour gold, from goldbearing sand.

It is well known that certain sands contain considerable quantities of gold, but in such fine form that it is dificult and, practically speaking, uneconomical to separate the gold from the sand by anyprocess heretofore known. It is an object of the present invention to provide a process and an apparatus whereby such gold may be profitably recovered from such sand.

It is a further object to provide a process and apparatus for the purpose stated which is capable of continuous operation, and which is therefore economical of the heat and power required.

With these and other objects in mind, as will appear hereafter, my invention comprises the novel process, and the novel apparatus and parts thereof, as shown in the accompanying drawing, described this specification, and as will be more particularly defined by the claims which terminate the same.

In the accompanying drawing I have shown typical apparatus embodying my invention in diagrammatic form.

Figure l is a general vertical section through apparatus, illustrating the operation of the process.

Figure 2 is a general plan view of the apparatus.

Figure 3 is a transverse section substantially on the line 3-3 of Figure 1.

Essentially the process comprises the drying of the gold-bearing sand until it will readily break up or fall apart into individual granules, and preferably by the application of heat to the sand, which heat is subsequently recovered, then forcing the gold-bearing sand beneath the surface of molten lead and its thorough admixture with the lead, so that when the sand is released, being of less specific gravity than the lead, it will float to the top, but the gold, being heavier, will remain in the lead, and will drop to the bottom of the container, and the subsequent removal of the sand from the surface of the molten lead. During this process there should be a continuous stirring of the mass to facilitate and encourage the breaking up of lumps of sand into individual granules, for by this means the gold may be segregated from the sand, and the individual granules of sand will, upon being divested of their gold, rise to the surface of the molten lead, where they can be removed as part of a continuous process, and the gold can from time to time be drawn off from the bottom of the 2, and in addition there may be provided a scraper 4 for removing the sand from the surface of the molten lead, an agitator 5 within the lead pot 2 to assist in mixing the sand and lead, and to reduce the volume of lead to a minimum, and a spout. 28 for withdrawing the collected gold, together with a portion of the molten lead to act as a vehicle for the gold.

The drier i may comprise a hopper it, into which the sand is dumped, a dome H within the hopper and provided with suitable means to heat it, as for example the oil burner 52 and outlet flue i9, baiiles It to spread the sand out into a comparatively thin layer, and a baffle l4 which is adjustable and which serves as a gate to admit sand, when suihciently dried, from the drying compartment into a chute l5.

After delivery by means of the chute E5, the sand passes into a conduit 3! whence it is delivered into a tubular housing 3i containing the feed screw 3. The latter is suitably rotated, for example by a motor 32 driven through gearing within the gear casing 33, to advance the sand down to the lower part of the pot 2. This pot contains molten lead L, and the upper part of the pot is connected to the upper part of the feed screw housing 3! by means of a passage or conduit 23, so that lead from the upper part of the pot 2 is carried over to the feed screw housing, and is continuously mixed with the sand as the sand, is being advanced by the feed screw into the lower part of the pot 2. This mixing action, in addition to thoroughly intermixing the lead and sand, serves to break up the sand into individual granules, so that when it is released from the feed screw at the bottom of the pot the sand, being of lower specific gravity than the lead, will float upwardly toward the surface of the lead in the pot.

Within the pot the member 5 is located to spread the lead into a comparatively small annular body. The member 5 is preferably rotatable, a motor 50 connected through gearing within the gear casing 5! being shown for the purpose, and

10 below the surface of the molten lead in the pot it carries cleats or projections 52 upon its surface which further assist in mixing the sand with the lead, as the sand floats upwardly, and in breaking up the sand into individual granules.

The gold being heavier than the lead, it will remain in the bottom of the pot 2, where it can be drawn oil from time to time through the spout 20, suitable valve or closure means 29 6, which may be heated by suitable means suchas the burner 60, whereby the lead is kept in a molten state at all times.

As the sand rises to the surface of the molten lead, and is forced above the surface by the buoyancy of sand from below, it will pass over an inwardly directed flange 6!, which prevents splattering of the molten lead, and will engage the baiile or scraper 4 as the sand is rotated by the rotary body 5, and the scraper will effect removal of the sand from above the surface of the lead, the sand running off down the chute 62.

Little lead is lost in this process, inasmuch as it will substantially all drain 01f the sand after the sand has passed above the normal surface level of the molten lead, but to replace any lost, or to charge the pot, I may provide a charging hopper 24, suitably covered, whereby pigs of load may be fed into the system from time to time, where, upon melting, it will mingle with the lead flowing through the conduit 23.

What I claim as my invention is:

1. Apparatus for the recovery of gold from sand, which comprises a pot to contain molten lead, a rotative body disposed in said pot to leave a relatively thin unobstructed annular space for the lead and sand, spaced cleats thereon moving in said annular space, but spaced from the pot, to stir up the lead and sand, and means to advance gold-bearing sand beneath the surface of the lead in said pot, whereby the sand will float upward and the gold will remain submerged.

2. Apparatus for the recovery of gold from sand, which comprises a pot to contain molten lead, means for receiving the gold-bearing sand and advancing it to the lower part of said pot, beneath the surface of the lead, whereby the sand will float upward, leaving the gold submerged, a rotative body largely filling the pot, to leave a comparatively thin unobstructed annular space for the lead and sand, and circumferentially spaced cleats on said body, extending generally lengthwise thereof to mix the sand with the lead in said annular space. 7

3. Apparatus for the recovery of gold from sand, which comprises a pot to contain molten lead, an inclined and enclosed feed screw adapted to receive gold-bearing sand and to advance it to the lower part of said pot, beneath the surface of the lead, whereby the sand will float upward,

leaving'the gold sl.1bmerged,and a passageconnecting the upper part of the pot and the upper end of the feed screw enclosure, for circulation of lead from the pot to the enclosure, and its admixture with the sand advanced by the feed screw prior to its delivery to said pot.

4. Apparatus forrthe recovery of gold from sand, which/comprises a pot containing molten lead, means to deliver gold-bearing sand to said pot near the bottom thereof, a body rotative about an upright axis and disposed in said pot to leave a relatively thin annular space for the lead and sand, and extending upward above the surface of the lead, a circumferential flange extending inward from the top of the pot, and terminating closely adjacent to said body, to leave an annular space for the reception of sand freed from gold, and means for removing sand from said annular space.

5. Apparatus for the recovery of gold from sand, which comprises a pot containing molten lead, means to deliver gold-bearing sand to said pot near the bottom thereof, a body rotative about an upright axis and disposed in said pot to leave a relatively thin annular space for the lead and sand, and extending upward above the surface of the lead, a circumferential flange extending inward from the top of the pot, and terminating closely adjacent to said body, to leave an annular space for the reception of sand freed from gold, a discharge passage leading from the upper side of said flange, and a baflle extending above and below said flange and lying closely adjacent to said rotative body, and conforming to the contour thereof to guide the sand for movement from the said annular space between the body and the flange to the upper side of the latter, and into said discharge passage.

ALBERT TRAYMAN. 

